Noncorrosive alloy and method of making and using the same



Patented Feb. 28, 1933 1,899,148

UNITED s'ra'rlezs PATENT OFFICE WILFOBD J. HAWKINS, 01 CLAIBORNE, MARYLAND, ASSIGNOR T AMERICAN MACHINE & FOUNDRY COMPANY, A CORPORATION OF NEW JERSEY NONCORROS IVE ALLOY AND METHOD OF MAKING AND USING THE SAME No Drawing. Application filed May 2, 1928. Serial No. 274,684.

This invention relates to the coating of It has been further discovered that by metal with non-corrosive and acid-proof profirst applying an undercoat of protective tective metal, and to the protective metals metal or alloy, such for example as lead conthemselves. taining approximately 4.5% of zinc and ap- 5 In certain localities where oil fields and proximately .5% of aluminum, and there- 50 attendant air conditions exist, as in Southafter applying a supercoat of protective ernCalifornia, Oklahoma and elsewhere, eX- m tal or alloy, uch for example as lead conposed metals of certain kinds, such as coptaining approximately 2% of phosphor-tin per and the ferrous metals, corrode much or approximatel 1% of phosmore rapidly than elsewhere, and the corrohid f l d, th i ll y 0 th nd o t 55 sion shortens their life and necessitates frei t t d b th l d f th supercoat quent and expensive y p ernent. against surface corrosion and closes all pin It h P 1n Practlce that P holes in the lead of the supercoat, thus pretlve coatmgs of of lead, Whlch are venting the corroding agent from reaching more. less efiePtlve elsewhere, q to p p and attacking the coated article during its y prsfiect artlclea 9 metal subiect to natural life. Metals, when rotected in this rosion in such localitles. It has been found manner, not only successfu 1y resist comm also that the ordinary coatings of zinc, or of sion i any atmosphere, but Successfully lead, wherever used, fail o p p y P sist attack by acids, showing no change what.- 65

tect articles of metal sub ec ted to the attack ever after 48 hours of immersion in a 2 9 g c An P P? for example, solution of sulphuric acid, which is the most if galvanized, or lead coated in the ordinary severe test known to science t l tested In 20% .solutlon of $111 One reason for preferring these particular acld for 48 hours W111 rendered protective metals or alloys is that the meltg g f fuflgler b the actlon of the ing point of the undercoat alloy is suflicientam urmg t i tune" 1y higher than'that of the supercoat alloy to It has been discovered that these d1fliculpermit the apphcation of the latter by the tles heretofore encimntel ed protectmg well known hot di ping rocess without dismetal agBJIISt COI'IOSIOII and acid attack, can P p e turbing the previously applied undercoat 7 be overcome by utlllzlng difi'erent character- Otherwise than y Softening it to permit it Y istics of different protective metals in such to penetrate or p g y p holes in the a manner that the weakness f each is fortifled by the strength of the )other, for lead; and these processes and materials are tectiv purposes It has been further cheap. Another reasonisthat the undercoat covered that one of these protective metals alloys Wlth h metal P the W bemg or alloys is far superior to any solder for coated E thls 1" 3Sults m deepemng h all ld i purp0ses sure of p1n holes in the lead, as well as in the Zinc, as originally used in galvanizing, is formatlon of a firm P Wlth the Protected itself subject to slow surface corrosion and e v to rapid destruction by the action of certain F ya the plzotefitlve undercoat 1S first acids. Lead, as originally applied as a coatpp y the hot pp g Pf and fi f ing, though non-corrosive, sometimes has after e supercoat 1S RP slmllal minute Fpin holes through which the corprocess, although the distinguishing charroding agent reaches and attacks the coatacteristics of the two alloys may be otherwise ed metal. utilized. The surface protected may be the to the undercoated metal a approximatel entire surface of the article, or any lesser part thereof needing protection.

Thus, there is produced a coating which achieves a protective result not obtainable by the use of either protective alloy alone, but only by a conjoint action of the factors of both. The article to be coated may be of any metal subject to corrosion, or to destruction by acids, and the protective metals or alloys maiy be of any kind suitable for the purpose.

n preparing the metal or alloy for the undercoat, lead is first melted/and then the zinc and aluminum are melted in the molten lead at a temperature of 875 F.- At this temperature the alloy is ready for article dipping therein.

In preparing the metal or alloy for the supercoat, lead is first melted and then the phosphor-tin is melted in the molten lead at a temperature of 750 F. At thistemperature the alloy is ready for article dipping therein.

Where still greater fluidity, tenacity and strength is desired, the lead phosphide is incorporated in the lead along with the phosphor-tin. It is,the supercoat metal or alloy which has been discovered to be more fluid, more tenacious and stronger than an, known solder for soldering purposes; an its use for this purpose is contemplated. The undercoating metal or alloy is somewhat less efiicient for this purpose, but may be used.

What is claimed is 1. The method of applying a non-corrosive and acid-proof protective coating to metal, which consists in first applying to the metal to be coated an undercoat of lead containing I approximately 4.5% of zinc and approximately .5% of aluminum at a temperature of approximately 875 F., and t n applying percoat of lead containing approximately 2% of phospigg-iin at a temperature of approximately 2. The method of applying a non-corrosive and acid-proof protective coating to metal,

which consists in first applying to the metal to be coated an undercoat of lead containing 4.5% of zinc and approximately .5% 0' aluminum ata temperature of approximately 875 F., and then applying to the undercoated metal a supercoat of lead containing approximately 2% of phosphorapproximately 2% of phosphor-tin and approximately .1% of lead phosphide.

6. The method of making an alloy suitable for solderin which comlprises adding phosphor-tin an lead phosp ide to molten lead in sufiicient proportions to form a lead allo containing approximately 2% of phospli or-tin and approximately .1% of lead phosphide.

In testimony whereof, I have signed my name to this s cification.

V lLFORD J. HAWKINS.

tin and approximately .1% of lead phosphide at a temperature of approximately 750 F.

3. ,A metallic product, comprising a metallic body provided with an undercoat of lead containing approximately 4.5% of zinc, and approximately .5% of aluminum, and with a sunrcoatpf lead containing approximately 2 o of phosphor-tin and approximately .1% of lead phosphide. V i

4. An alloy consisting of lead containing approximately 4.5% o zinc and approximately .5% of aluminum.

5. r. alloy consisting of lead containing 

